Combined rheostat and switch device



Dec. 16, 1941. .I B, G, COCHRANE 2,266,412

COMBINED* RHEOSTAT AND SWITCH DEVICE Filed March s, 195s 2 sheets-sheet 1 z'l ze 4Z 7 as zo 42 45 2z 24 Z5 8 l L 7" 4Q 29 l t l 55 l 111| L 5f l1. M -2 H: sz

INVEJTOR er 050071171214),

A-TToRNE Dec- 16 1941- B. G. cocHRANE 2,266,412

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INVENTOR CEM@ ATTORN E Patented Dec. i6, lgfif` UNITED existir o commen nnnos'rs'r AND SWITCH nevica Bert G.. Cochrane, Ghicago, lll., assigner to Casco Products Corporation, poration of Connecticut Bridgeport, Conn., a ooi'- Application March 3, 1938, Serial No. 193,661

1G Claims.

od poirc-csi; upon or 'ng element bhrongh a losing individual coat-acts esult of such movement.

The resistance-carrying invention is designed to comple resistance unit and is provided .f of contacts connected to the resistance unit. With this construction, circuits can be completed through the resistance unit without haring con tacts rubbing over the surface thereof. The contacts carried by the resistance-carrying element cooperate with the contacts carried by the housing, and, with a minimum movement, will close a plurality of circuits which will include various portions of the resistance unit. The contacts carried by the housing are formed as detents and cooperate with the contacts on the resistancemember is secured to a sliding actuator so form substantially a plunger-like element longitudinally slidable the housing. The actuator lfor the element has indicating means thereon to show the condition of the circuit for each post tion of the movable .member in the housing.

in some instances. it is practical to nso a longitudinal siiflaele actuator because o? li' space requirements. accordingly, of the invention rotatably meente nested itudinal View si switch partly in elevation and partly section..

Fig. 2 is a View similari` to l, but showing the switch entirely in section in full on or rst circuit-making position.

Fig. 3 is an enlarged cross-sectional View taken on line 3-3 of Fig. 2.

Fig. 4 is an enlarged rear elevation of the switch.

Fig. 5 is a View showing the control knob in elevation.

Fig. 6 is a plan View of a portion of the housing showing the relative positions of the resistance coil contacts with respect to the detente.

Fig. '7 is a View of a inodiied form of the invention, the view being similar to that of Fig'. 1.

Fig. 8 is a Vertical sectional view of the device. shown in Fig. 7.

Fig. 9 is an exploded view of the translating means for converting the rotary movement of t'o slidablyreceive the contact stud 26 and supthe actuator into the longitudinal movement of the mol able member,

Fig. is an assembled view of the elements shown in Fig. 9.

Fig. 11 is an end view of the actuator showing the indicating positions.

The combined rheostatand switch device of the present invention is adapted to be mounted on a support in a position in which it can be readily operated. In the preferred form of the invention. the mounting means comprises a tubular housing of sheet metal or the like having an open end provided with exterior threads 2l, Adjacent the open end of the housing, a plurality of tangs 22 are struck outwardly. 'Ihe housing is mounted on the dashboard 23 or the like support by being inserted through an aperture therein until the tangs 22 contact the back thereof. A collar or escutcheon plate 24 is threaded on the open end of the housing so as to 20j lock the dashboard against the tangs 22. I'he other end of the housing is closed by means of a transverse wall 25 in which an elongate contact stud 23 is mounted. The contact stud 25, having a reduced portion at one end thereof, is provided 25 with a band of insulating material 21. 'I'his band is mounted on and surrounds the reduced portion andls locked in place by a nut 23 threaded on the stud and contacting the insulating band to. l

clamp it to the contact stud. The contact stud si)l is mounted in a central aperture in the transverse wall 25 and is insulated therefrom by insu-` lation 29. The Ainsulation and the contact stud are locked in place in the rear wall by means of a nut threaded on the projecting end of the contact stud which draws the nut 28 into clamping relation therewith.

The contact stud is connected to a circuit including the device tobe controlled by means of f a connector lug 3l secured to a conductor S2 of the circuit. The connector lug is positioned on the projecting end of the stud and locked in place thereon by a nut Sti.

The housing is-provided with a longitudinal *Y 33h is positioned in the member and has the other end of the resistance element connected thereto.

With this construction, the resistance element will be entirely protected from any rubbing action of the contacts along the surface thereof, when it is inserted in the circuit. The resistance element will be flxed in place and completely enclosed and connected into circuits through the contacts mounted on the member and connected to the element.

These contacts can be secured in the member as desired. The herein preferred form of the invention showsthe contacts locked in place by nuts 39. The member is provided with aplurality of openings 4l through which a screw driver or other implement' can beinserted`toengage the contacts when they are being secured to the member. These openings also serve, whencooperating with the openings 42 in the housing. as vent openings through which air can circulate to cool the resistance element when the latter slot 34 extending substantially'the full length thereof for a purpose to be later described.

'I'he member for supporting the resistance. in

the present preferred device, comprises a tubular movable member 35 of insulating material adapted to be slidably mounted in the housing. The inner end of the tubular member, or that end ad y jacent the wall 25, is provided with a plug t@ of metallic material secured in the bore of the member and provided with an aperture adapted port the member for movement therealong.

The member 35 carries the resistance element or unit. In the herein preferredform of the invention, the resistance element or unit comprises an elongate coil of resistance material. 31 60 disposed in the bore of the hollow insulating member. 'I'he movable member I5 has positioned, at spaced points therealong. and in alignment, a plurality of contacts 33, 38a and 33h. The contact 38 is conneoted'at the inner end of the housing and has the inner end of the resistance element secured thereto. This contact also has an outwardly projecting contact 40 adapted to engage the contact 28 to close a circuit from the contact 23 to the contact 38. In normal position of the member 35 in the housing, the contact 40 will rest on the insulating sleeve 21. The contact 38a is secured intermediate the ends of the member 35 and is connected to thefintermediate 1 is connected in a circuit and energized.

'I'he member 36 can be longitudinally moved in the housing in many ways. In one form of the invention, it is connected directly to an actuator for longitudinal movement therewith. In this form, a metal sleeve 45 has a reduced portion 43 threaded into the outer end of insulating member 35. This sleeve is of such outside diameter that it engages the tubular housing. The other end oi.' the metal sleeve has a reduced portion 41 which is threaded into the hollow bore of a translucent actuating member 49.

With this construction, the insulating tube carrying the resistance element is directly connected through the medium oi the metal sleeve y45 with the actuator d@ so that sliding movements imparted to the actuator will result in movement oi the insulating member and resistance to the various circuit-closingpositions which will later 'be described.

A contact carrier 50 of insulating material is supported by the housing and is positioned over the longitudinal slot 35 of the housing so as to close the same. 'I'he contact carrier is provided at the housing-engaging portion with shoulders Ei, as is seen in Fig. 3, which engage the edge of the slot 34 and prevent relative movement between the housing and the contact carrier. Two tangs 52, which are struck out from the housing at the ends of the slot, are bent over the shoulders on the end of the contactl carrier 50 as shown in- Fig. 2. This securely locks the contact carrier in place.

The contact carrier is provided with a longi-l tudinal slot 53 extending substantially the full length thereof and opening into the interior of the housing. This slot will receive the projecting contacts 38. 33a and 38h carried by the member 35 and prevent relative rotation between the housing and the member 35 while permitting the desired longitudinal sliding movement.

The contact carrier has a plurality of openings 53a which are spaced therealong and open into the slot. A contact bar 54 is secured to the underside of the carrier 50 by rivets 55 or the like and has a plurality of contacts 53, 58a and 53h secured thereto and project through the openings 53a into the slot 53 to be engaged by the contacts 33, 38a and 38h, when the latter are moved along the slot to complete circuits through various portions of the resistance element.

The inner end of the contact bar is bent to portion oi the resistance wire: and the contact 76 form an ear 60. 'I'he contact bar is connected in the circuit of the device to be controlled by means of a connector lug 6| secured to a conductor 62. The connector lug is locked to the ear B by means of a screw $3.

'Ihe contacts, as shown in Figs. 3 and 6, have a nat portion by which they are secured to the contact bar as by rivets l. Each contact is formed with a generally arcuate contacting surface 65 extending longitudinally of the slot. The arcuate face is provided with a central depression or detent 6B to be engaged by the contact 38 when the latter is moved to the desired circuitclosing position. These contacts are resilient so that the contact 38 can pass into the depression or detent 'without dilliculty, and the resiliency of the contact will hold the contact 38 and it connected movable member against accidental longitudinal movement.

The contacts are spaced along the contact carrier in such a manner that only one contact will be made at a time, and that will be with the corresponding contact mounted on the longitudinally movable member.

All of the circuits, because of thisfrelation of contacts, will be made upon movement' of the resistance element for only a small portion of its length. This is in contradistinction to the current type of combined switch and rheostat in which the resistance element must be moved a distance equal to its length in order to connect the whole resistance element into circuit, and is of great importance since it insures quick oper ation and conservation oi space.

This relation between the contacts can prohably be seen more clearly from the description oi the operation of the switch going through all of the circuits made therein and controlling the operation oi the device to be controlled.

One side oi circuit Will he closed by the Contact tu engaging contact its T fili be seen in Figs. l and 2, when the member is in its normal deep position in the housing, the contact it `will be resting on the insulating sleeve 2i, and thus no circuit can be completed between the two conductors leading to the device to be coritrolled, even though one oi the contacts t, Stic and 38h and its cooperating contacts 5t, 56a and 55h might be accidentally closed. These latter contacts are so positioned relative to each other that they wiil be normally rendered successively operative. In other words, the contacts on the movable member are equally spaced while the contacts on the housing are spaced relative to the corresponding contact on the movable member so that, upon successive movements of the Y movable member, the next contact will be made with its corresponding contact on the carrier.

With the device in deep position as shown in Fig. l, the circuit is open because the contact 43 is resting on the insulation 2l and contacts carried by the movable member and the container carrier are disengaged.

Upon movement of the movable member outwardly to the iirst position, the contact 4G will be moved from the band of insulation 2l and will engage the contact 26 and close the circuit therethrough, and simultaneously contact 33 will engage contact 56 and close the circuit theren through,` as is shown in Fig. 2. In this position of the movable member, the circuit extends from the conductor 32 through the contact 2G, contact 40, contact 38, contact 56, to conductor 62,'

and does not include any resistance in the circuit.

As shown in Fig. 2, contact 38a is one step away from contact 56a, and contact 38h is two steps away from contact 56h. Upon movement of the movable member outwardly to the next position, it will be seen that contact 38a will engage the arcuate face of contact 56a prior to the circuit being broken at contacts 38 and 56. When the contact 38a is engaged by the detent 56 of contact a, the circuit through contacts 38 and 55 will be broken. In this position, the circuit will extend from conductor 32, through contact 26, contact 40, contact 38, through a portion of the resistance element 31, through contact 38a, contact 56a, contact bar 54, to the conductor 52 and a portion of the resistance will be inserted in the circuit of the device to be operated so that the latter will be operating, for example, at a medium rate of speed. When contacts 38a and 56a are engaged, contact 38 will be one step past contact 56 and contact 38h will be one step before 55o. When the movable member is moved to its extreme outermost position, the contact 38h will engage contact 56h, and will be made just prior to opening of the circuit at the contacts 38a and 56a. The circuit now set up will extend from the conductor 32, through the contact 26, contact 40, contact 38, through the entire resistance element, to contact 38h, through contact 56o, to the conductor bar 54, and to the conductor 62 and all of the resistance will be inserted in the circuit containing the two conductors 32 and $2. The device whicii is controlled thereby will then operate at a low rate or From the above description, the stepped relas t tion ci the contacts on 4he Contact carrier respect to contact for erecting dirle four different circuits i -l movenient between the p compact and easily operated control device.

The movaifile member, it will be seen, will have four effective positions operation of the device, namely, oni when the circuit is opened; high when thecircuit is iirst closed directly through the contacts and 5t; medio-im, when the circuit is closed through the contacts 39o; and 5ta; and I OW, when the circuit is closed through 38h and in the preferred form of the invention, the actuator is provided with plurality oi' hands llc, No, Tic, 'ilc or indicating means marked of high, medium and lowf Thesebands will be exposed, as shown in Fig. 5, when the actuator and its connected movable member are moved to the desired posithe movable member t circuits v/ili provide minimum or relative tion in the housing to close a circuit and will give an indication of the position of the switch and rheostat means.

A signal is provided for indicating when the crcuit is closed through the switch and rheostat. Since the switch and rheostat are usually positioned in a circuit for controlling a device, for example, a defroster or car heater, it is desirable to have a signal when the device is on. This signal may be of any desired form, but, in the preferred form of the invention, it comprises a means for illuminating the translucent actuator 4s during the entire period when the circuit through the switch is closed. This is accomplished by mounting a lamp 10 in the hollow of the movable member actuator.

In the preferred form of the invention, a contact disk il, having a contact Ha extending into a position to be engaged by a contact 'l2 oi' the lamp, is mounted at the outer end of Imember 3e adjacent the sleeve 45 but insulated therefrom.

ts, thus producing a.

The contact disk is connected by means of a conductor 13 to the contact 33. The shell 14, or other contact of the lamp. is threaded into or otherwise secured tothe metal sleeve 45 which contacts the housing and thus forms a ground.

for the lamp circuit. At all times when the contact 33 is connected to the conductor 32 through the stud 23, the lamp will be energized through the conductor 13, through the contacts 1i, 12 through the lamp, to the netal sleeve 4B and hence to ground and will indicate that a circuit is closed through the rheostat and switch.

As will be 'seen in Figs. 1 and 3, a tang 18 is lanced from the Aside wall and bent inwardly so that it bears against the movable member to steady the same against accidental jarring and moving in the housing.

In the form oi the invention shown in Figs. 7 to 11,the movable element is mounted in the housing for longi udinal movement and is adapted to close a p urality of circuits as in the previous form of the invention. In this form, however, the-movable member is connected to aM rotatable actuator, which is mounted in the housing in such a manner, that, upon rotation of the actuator, the movable member will slide longitudinally in the housing.

The housing 20a, in this form of the invention, is provided adjacent its open end with an internal rib 80. Surrounding the-open end of the housing is a threaded sleeve 8| which is secured thereto in any desired manner. The sleeve has a backing nut 82 threaded thereon and is positioned in an aperture in the dashboard 23 or similar support with the nut 32 in engagement with the back of the dashboard and is locked in place therein by a collar 83 threaded on the cute/r end thereof. `An internal ring 84 is threaded in the open end of the-housing 20a, and, together with the internal rib, form a channel for rotatably mounting the actuator and holding the same against sliding movement in the housing.

The movable member 35 of insulating material may be connected to the rotary actuator in any manner. In the preferred form, the member 35 has a sleeve 81 threaded4 on its outer end. The

' sleeve has a reduced portion 88 which is provided with a helical cam groove 89 extending tothe end thereof. 'I'he diameter of the threaded end of the sleeve is such that it'makes contact with the housing. Positioned in the bore of the sleeve is a lamp socket 90 for receiving the lamp 9|.

A hollow translucent actuator 93 has a sleeve 34 positioned in the-bore thereof. The sleeve has an outwardly extending shoulder 95 which is adapted to extend between the internal rib and the ring 84 `to hold the actuator against sliding movement in the housing while permitting it to lbe freely rotatable therein.

The sleeve 94 has an inwardly projecting member 96 which engages the cam groove so that, upon rotation of the actuator, the projection operating in the cam groove will translate the rotary motion of the actuator into longitudinal sliding motion of the movable member 35 in the housing and cause the contacts on the movable member to successively engage the contacts on the housing to close the predetermined circuits.

As viewed in Fig. 11, the actuator is marked to indicate the om high, .mediurn" and low positions of the switch and rheostat. The lamp 9i, as shown in Fig. 8, is adapted to be energized whenever a circuit is closed through the switch and rheostat and illuminate the translucent the housing: an actuator carried by the housing; l

actuator at all times when a circuit is closed through the device. This is accomplished in the same manner as described in the previous form of the invention. The markings will stand out very clearly on the illuminated actuator and the position of the movable member and. conse-v` quently, the circuit that is closed can be )readily ascertained.

Variations Fand modifications may be made within the scope of this invention and portions of the improvements may be used without others.

l. In a combined rheostat and switch device, a housing having a contact `secured to the end wall thereof and projecting into the interior of a member operatively associated with and longitudinally movable by the actuator; a resistance element carried by the member; a plurality of contact means carried by the member and respectively connected to the resistance at spaced points on the latter, said contact means including a contact adapted to engage the contact connected to the end wall of the housing upon movement of the element from a normal position; and a plurality of contacts carried by the housing and cooperating with the said contact means for` selectively connecting diierent portions of the resistance element in a circuit upon movement of the actuator from the normal position.-

2. In a combined rheostat and switch device, a housing having a contact secured to'the end wall thereof and projecting into the interior of the housing; an actuator carried by the housing; a member of insulating material operatively associated with and longitudinally movable by the actuator; a resistance element lcarried by the member; a plurality of spaced contact means carried by the member and respectively connected to the resistance at spaced points on the latter, said contact means including a contact adapted to engage the contact connected to the end wall of the housing upon movement of the element from a normal position; and a plurality of contacts carried by the housing and cooperating with the spaced contacts for selectively connecting different portions of the resistance element in a circuit upon movement of the actuator from the normal position.

3'. In ajcombined rheostat and switch device, a housing; an actuator rotatably supported by the housing; a hollow member operatively associated with the actuator to be moved thereby; cam means interposed'between the actuator and the member whereby rotary movement of the actuator is translated into longitudinal movement of the hollow member; a resistance element disposed within said member; a plurality of contacts carried by and uniformly spaced along said member and respectively connected to the resistance element at spaced points on the latter; contact means on the housing comprising a plurality of contacts spaced apart a distance slightly greater than the contacts on the member to cooperate seriatim with the contacts on the movable member to close a predetermined electrical circuit when the member is moved slight distances to any one vof a plurality of positions; and resilient detents for holding said member in any one of the plurality of positions after the same has been slidably moved thereto by rotationA a housing; a hollow actuator carried by the.v

said actuator;

housing; a light mounted in the hollow actuator; a tubular memberl operatively associated with and longitudinally movable by the actuator; Va cylindrical resistance element carried by said tubular member; an elongated contact secured to the end wallof said housing, said elongate contact being telescopically received by the resistance element carried by said tubular member; a plurality of spaced contact means carried by the member and respectively connected to the resistance at spaced points on the latter, said contact means including a resilient contact adapted to continuously engage said elongate contact during displacement of the element from a normal position resulting from operation of means for closing the circuit through the light upon engagement oi said resillent contact with said elongate contact; and a plurality of contacts carried by the housing and cooperating with the spaced contacts for successively connecting different portions of the resistance element in a circuit upon movement of the actuator from the normal position.

5. In a combined rheostat and switch device, a housing; an actuator movably mounted on the housing; a member supported within the housing by the inner walls thereof for longitudinai sliding movement and operatively associated with the actuator to be moved thereby, said member having means thereon including a plurality of spaced dependent contact pins; a resistance element carried by said member and having different points thereof connected respectively to each of the contact pins; and means on the housing, including a slot formed longitudinally oi the same adapted to receive said pins and spaced contacts disposed in said slot, adapted to cooperate With the pins on the movable member to close a circuit and connect diferent portions of the resistance in a circuit when the actuator is operated, said contacts being pos cned within the slots so as not to interfere wi i the sliding movement of the slidable member.

6. In a combined rheostat and switch device, a housing; a manually operated plunger sup ported by said housing; an elongate resistance element carried by said plunger; a plurality of contact means connected respectively to diierent points of said resistance element at spaced intervals therealong and projecting at spaced intervals from the plunger; and means mounted on the housing adapted to receive said contact means, said means including a slot formed longitudinally of said housing and a plurality of spaced contacts carried therein. in different mutual spaced relation than the contact means on the plunger and adapted to selectively cooperate with the projecting contacts on the plunger when the plunger is slidably moved in the housing to a plurality of positions to thereby connect a predetermined resistance in a circuit, said projecting contact means being cooperable with the Walls of said slot to retain said plunger against turning movement relative to said housing and to maintain the contacts in position to engage the cooperating contacts. f

7. In a combined rheostat and switch device, a housing; an actuator carried by the housing; a member operatively associated with and longitudinally moved by the actuator; a resistance element connected to the member for movement therewith; a plurality of spaced contacts carried by the member and connected to said resistance element at different points therealong; and col operating contacts carried by the housing, said 5 contacts being spaced on the housing at different intervals than the contacts on said member so that, upon movement of the member out of its normal open-circuit position, a. contact is made to close the circuit, and further movement of the member from normal position causes a second contact to be made just prior to the opening of the first contact and inserts a portion of the resistance in the circuit, said last-named contacts comprising resilient detent means for yieldingly engaging the rst-named contacts and retaining the member in the selected circuit-closing position, said detent means adapted, upon movement of said member from one selected circuit-closing position to a second circuit-closing position, to release the rst engaged contact just prior to the engagement of the contact by the detent means of the second position.

8. In a combined rheostat and switch device, a housing; an actuator rotatably supported by the housing; a hollow member operatively associated with the actuator to be moved thereby; cam means interposed between the actuator and the member whereby rotary movement of the actuator is translated into longitudinal movement of the hollow member; a resistance element disposed within said member; a plurality of uniformly spaced contacts positioned along said member and connected respectively to diierent points on the resistance element; and a plurality of contacts on the housing spaced apart a distance .slightly greater than the contacts on the hollow member to cooperate seriatim with the contact means on the hollow member to close a predetermined electrical circuit when the meinn ber is moved to any one of a plurality of posi tions, the Contact means on the hollow member also operating to prevent rotary movement of said member caused by the actuating member cooperating with the cam to move the cam.

9. In a combined rheostat and switch device, a housing; an actuator rotatably supported by the housing; a member associated with the actuator to be moved thereby; means interposed between the actuator and the member for changing the rotary movement oi the actuator into longitudinal sliding movement oi the member; a re sistance element carried by said member; a plurality of longitudinally spaced contacts carried by said member and connected respectively to diierent points on the resistance element; and contact means on the housing including a pluraln ity of longitudinally spaced contacts, one for each contact on the member, adapted to selectively engage With the contacts on the member to connect dierent portions or" the resistance element in a circuit upon predetermined operation of said actuator, said contacts on the housing having different spacing than the contacts on said member to cause seriatim engagement therebetween, the engagement between said contacts of the member and the contact means of the housing retaining said member against rotative movement when said member is slidably moved by rotation of said actuator.

l0. In a combined rheostat and switch device, a housing; an actuator movably mounted on the housing; a member operatively associated with the actuator to be moved longitudinally thereby; a resistance element carried by said member; a plurality of spaced contacts carried by said member, each of said contacts being connected to a diierent point on the resistance element; and contact means on the housing adapted to cooperate selectively with'the contacts on the mov= able member to connect diiierent portions the resistance in a circuit when the actuator is operated, the'contact means on the housing inciuding a plurality of resilient detent means for yieidingly engaging and holding the contacts of said member. the contacts on the member and 5 through the ydifferent portions oi the resistance element, and said detent means adapted, `upon movement of said member from one ciruitsclosing position to the next, to release the previously engaged pair ot contacts Just prior to the engage- Y ment of the next pair of contacts and their associated detent means.

' BERT G. COCHRANE. P 

